What are the differences between two doses of COVID-19 vaccine and three doses of COVID-19 vaccine

The effect of two or three injections of COVID-19 vaccine is good

The effect of two or three injections of COVID-19 vaccine is good. Only two different dosage forms can prevent COVID-19 infection. At present, there are three commonly used dosage forms, one dose, two doses and three doses of COVID-19 vaccine. Two injections of the new inactivated coronavirus vaccine are required. Generally, the interval between the first injection and the second injection is more than 3 weeks. The second injection should be completed as soon as possible within 8 weeks after the first injection. The recombinant subunit COVID-19 vaccine needs three injections. The interval between the first injection and the second injection, the interval between the second injection and the third injection is recommended to be more than four weeks. The second injection should be completed within eight weeks after the first injection. The third dose should be administered within 6 months after the first dose and can produce sufficient antibodies to combat potential exposure to the coronavirus.

Difference between two needle and three needle

Technical route difference.

The two injections of COVID-19 vaccine refer to the inactivated vaccine, which is prepared by first expanding COVID-19 in cell culture, then inactivating and verifying it, and finally purifying and extracting it.

The term "three injections" refers to recombinant protein vaccines, which use genetic engineering technology to construct engineered cells expressing the virus S protein or its receptor binding epitope, and then cultivate the cells in large quantities before extracting and purifying the protein to make vaccines. Vaccines with different technical routes have differences in vaccine components, production processes, immune mechanisms, and immune programs, which is why there are differences between two and three doses.